Cohors III Delmatarum equitata c.R. pf

Cohors III Delmatarum equitata c.R. pf
Roman infantry helmet (late 1st century)
Active	early 1st century to at least mid-3rd century
Country	Roman Empire
Type	Roman auxiliary cohort
Role	infantry/cavalry
Size	600 men (480 infantry, 120 cavalry)
Garrison/HQ	Germania Superior 80-134; Dacia 179-257

Cohors tertia Delmatarum equitata civium Romanorum pia fidelis ("3rd part-mounted Cohort of Dalmatae Roman citizens, dutiful and loyal", abbreviated COH III D), was a Roman auxiliary cohort mixed infantry and cavalry unit.

It was named after the Dalmatae, an Illyrian-speaking tribe that inhabited the Adriatic coastal mountain range of the eponymous Dalmatia. The ancient geographer Strabo describes these mountains as extremely rugged, and the Dalmatae as backward and warlike. He claims that they did not use money long after their neighbours adopted it and that they "made war on the Romans for a long time". He also criticises the Dalmatae, a nation of pastoralists, for turning fertile plains into sheep pasture. Indeed, the name of the tribe itself is believed to mean "shepherds", derived from the Illyrian word delme ("sheep"). The final time this people fought against Rome was in the Illyrian revolt of 6-9 AD.

The revolt was started by Dalmatae auxiliary forces and soon spread all over Dalmatia and Pannonia. The resulting war was described by the Roman writer Suetonius as the most difficult faced by Rome since the Punic Wars two centuries earlier. But after the war, the Dalmatae became a loyal and important source of recruits for the Roman army.

According to Holder, a total of 12 cohortes Delmatarum appear to have been raised after the suppression of the Illyrian revolt in two series, of 7 and 5 respectively. All these units were in existence by the time of emperor Claudius (r. 41-54) Of these, 9 appear to have survived into the 2nd century.

The regiment was probably raised by founder-emperor Augustus (r. 30BC-14AD) after 9 AD. It was certainly in existence by the time of Claudius (r. 41-54). Its early movements are unknown.